Process of manufacturing cementitious material



I 3,6213136, Sept' 2D 1927 H. s. SPACKMAN PROCESS OF MANUFACTURING CEMENTITIOUS MATERIAL Filed Sept. 22A 1923` A n m utenheitl 2h, M27

rillliitilililiii eine.

ilrrniuiur uit .Applieation tnel Eeptcniuer 22, 1823 Serial No. 664,253.

This invention relater particularly to the manufacture in furnaces or lrilns or the rotary type, of cements ot the ltiuol commonly known es elumnate comente that in nements in which the alumina, exceeiie the silice und in which the lime present after -tlelucting @that cornhinefl with the silicn und; other nciil lll , volvera.

noting elements is only suilicieut to combine with uluminu in ratios from tiAlml/.im 3Go() to CaUAlmg.

One object. of the invention is toprovitle o. practical. economical and e licient procese for reducing low linie nluminz'iur; cemento.

T e rotary lriln as customarily usetl for the cnlcinntion oit tortlentl Cement. lime, etc., consiets oi e hollow revolvingcylinder lined with L refractory rnnteriui und so nion'i'iteti that it is inclined from itu ieerling to itel discharge end, the incline (ruining the charge of material feti into its upper end to more progressively through it no it relhe steepness of the incline :is in general use varies; from one-quarter inch to three-quarters of en inch to the foot.

Such rotary kilns customarily vary .in di. nineter from six 'to twelve feet und their length 'is 'usunll'v from one huntlrerl to two hunirefl nml titty feet. But in general the length bears a definite relation to the internal diameter, i; e. the distance hetween opposit@l portions o: the refractory liringf. It the ilry proree's ie employed, the ratio o diameter to length is customarily equal lo or greater than one to fifteen. lli/"hen the wet process is usech und the niuleriul to he cnlcineil is inixosfi with water 'prior to heilig fed to the kiln. the ratio otn the climnctrr 'to the length is ciwtonmrily equini to or greater thun one to twenty.

`While kilns'. oi the above noteil geom-nl lcherector here been Standard in 'the lortlumi courent industry, in spite of numerous cxl'icriiuenl's: they have not heretofore lief-n found practicable for the conuuercinl production of low linie hiu'h uluminouf comente. Such cemento h v reason oi their murltwlly different rlicn'iicnl composition. hure u relutycly email tenuiernturc ronge hetweou the point of incipient ine-ion anrl tho uotunl melline' point. ihis tcinporuture range in oni-- tuoni)y consifilcreil tio oorer less than o0" l". ils :i consequence. when attempts here heen nuiflc to culeine low linie high uluiniiwus; cemento in u rotary kiln in the usuel nuur ner, it hns been found impossible to no control the temperature es to maintain constantly within the narrow ronge permitted. This not only ,gives un unsu'tiinctory procluet due to lool: of uniformity, out nileets the mechanical operation oi the lriln which rings up hntlly. m

with the uniform prut-enge of the material through the lcilln, thereby cutting' down the tirait und` greatly lowering' its output, not only hy reason or' the relatively Small amount of materiel poseert through the kiln, hut oleo hccnusso oi" the necessuirjr und irequent shutting' down :intl coolingr of the kiln in orilcr lo permit the innnunl cutting; out of the ringe thut have luren formeel. Such irregul-.ir operation. besides resulting in n reduced output oi unsntistnctor' rlliiterinl, greatly iurrcnsfes the amount of fuel. required for the I 'u'oifiuetion oi." :1. barrel of' cement und likewise nintorinlly increases the labor coste. .n.5 o consequence, srnelting iurnnces have lies-n customarily usefl for the conunercinl umnufncture ot' low lirnehigh nluininous ceinenl's.

Owingr to the inueh higher lime contento Portland cemento which causen the mnteriel to attack the ordinary lire brick linwhen the heat in the liln is raised sufli ciently high to fuse the materials therein., fusion in rotury kilns has not heen resorted to in the manufacture of Portland Acement. I have discovercrh however, that owing to its low lime content,` low linie high alumina cement run he hrougi'ht to u State of 'fusion in n rotary lciln without serious (langer or illumine lo the lining; thereof.` :ruil that when in culeininy; louv linie high nluiuinu cement, the temp-cinture ie: corrieri sufiicicntlj,v high to produce turion. it 'ift' iosoil'ile to protluce o. uniform rement, with little or no trouble from ringing. ln. using fue term 'l'i'ising in thisl specifiention I hure intenrlefl` to (lefinc the comlilion oi luirlity resulting from the notion ot heut :xml in which the charge .lo'usi eulliciently freely to become thoroughly rnixorl und substantially homogenousas :i result oi' agitation cruised hy the rotation oi' the lui-noce :unl in which it is free from :t tenrlcricy to agglomeratie or adhere to the sides of l-hc kiln in luigre mussen. 'lhe tenopernturc rctuiircil for bringing` `the charge to thi??` condition will vary Widely' with it@ composition. hut. in general it muy loc eluted that thie tcinpemturowill ronge between npi'n'eminiutcly S2500" uml 30000 F. I have also iliecoreretl thnt hy reducing; the length of the lqiln unil, operuting' it et it suitable lilo 

